Molding-sand gas-hardening apparatus



Oct. 25, 1960 Filed July 12, 1956 NI KIA TCHEN 2,957,212

MOLDING-SAND GAS-HARDENING APPARATUS 3 Sheets-Sheet 1 INVENTOR.

Ni Kio Tchen ATT'YS Oct. 25, 1960 NI KIA TCHEN 2,957,212

MOLDING-SAND GAS-HARDENING APPARATUS Filed July 12, 1956 3 Sheets-Sheet 2 W f 23 g a FIG. 7 43 39 C I2 48 INVENTOR:

- Ni Ki 0 Tchen 42 ATT'YHS Oct. 25, 1960 N! KIA TCHEN MOLDING-SAND GAS-HARDENING APPARATUS 3 Sheets-Sheet 3 Filed July 12, 1956 3 A 2 w u 0 m 2 A ll m Q 6 o o b ax @0 L M m w \\\\X\\\\\\m I a l m V 6 a m G A n w FIG. 9

ATT'YS United States Patent MOLDING-SAND GAS-HARDENING APPARATUS Ni Kia Tchen, 97A Chungking Road S., Section 1, Taipei, Taiwan, China Filed July 12, 1956, Ser. No. 597,441

Claims. (Cl. 22-9) This invention relates to apparatus for injecting CO gas into molding sand to effect its quick hardening preparatory to the pouring of molten metal for casting forms.

The main objects of this invention are to provide an improved apparatus for injecting CO gas into and dispersing it through sand packed in molding flasks; to provide an apparatus of this kind having improved means for penetrating the sand to form a plurality of dispersion points interiorly of the flask-supported sand at various points around the patterns; to provide an apparatus of this kind having improved means for introducing the CO gas into the sand after channels to the dispersion points in the flask-supported sand have been formed; to provide an apparatus of this kind having improved sand penetrating-and-gas-dispersion means which is sealed against the entrance of sand into the gas-introducing means during the formation of the channels to the points of gas dispersion in the sand; and to provide a molding-sand gashardening apparatus of this kind which is extremely simple in construction, hence very economical to manufacture and capable of facile use by unskilled labor without likelihood of failure in effective results.

In the specific adaptations of the invention shown in the accompanying drawings:

Figure 1 is a vertical, partly-sectional elevation of a primary adaptation of an apparatus constructed in accordance with this invention in use with the drag of a molding flask;

Fig. 2 is a similar view of the apparatus in use with the cope of a molding flask;

Fig. 3 is a transverse plan view of the drag mold taken on the plane of the line 3-3 of Fig. l; the patterns having been removed;

Fig. 4 is a plan view of the cope mold, with the patterns removed, taken on the plane of the line 4-4 of Fig. 2;

Fig. 5 is a plan view of the gas-chambered needle supporting and carrying member;

Fig. 6 is a view similar to Fig. 2 but showing a modified form for use with patterns of difiering sizes;

Fig. 7 is a fragmentary, sectional elevation of a modified form of sand-penetrating element with a valve controlled gas-dispersing outlet;

Fig. 8 is a diagrammatic modification of the form shown in Fig. 7 wherein manual valve-retracting means supplements the gas-pressure retracting valve means, the valves being shown in retracted or open position; and

Fig. 9 is a plan view of the same.

The essential concept of this invention involves a hollow supporting member for superimposed registration on the parts of a molding flask and wherein is formed a gas supply chamber communicating with a plurality of needle elements mounted on the supporting member for pressure penetration into the molding sand and forming gas flow channels from the chamber to the dispersion points in the sand.

A molding-sand gas-hardening apparatus embodying the foregoing concept comprises, a flask-supporting frame 2,957,212 Patented Oct. 25, 1960 11, whereon a drag 12 and a cope 13 may be interchangeably arranged, and a gas-chambered member 14, mounting a plurality of channel-forming and gas-dispersion or needle elements 15, rotatably suspended on a reciprocable yoke 16.

The flask frame 11, as herein shown, comprises a base plate 17 supported on standards 18 having posts 19 extending upwardly therefrom. The size and overall arrangement of this frame will be determined by the size of the flask which is to be used and which, of course, will be controlled by the size and number of castings that are to be simultaneously formed in the mold.

The drag 12 and the cope 13 are more or less conventional structures, except that each is formed with lateral ear-like extensions 21 at opposite sides which are apertured to fit over the posts 19 so that these two parts of the flask are set in identical registering positions on the base plate 17 for packing sand around the patterns P.

The gas-chambered member 14 is a hollow rectangular body having a chamber 26 to which CO gas is admitted through an inlet 24 from a valve-controlled source of gas under pressure (not shown). At the opposite ends of the member 14 are integral extensions 22 which are apertured to fit over the posts 19 and terminate in trunnions 23 whereby the member 14 is rotatably suspended on the yoke 16. The apertured extensions 22, fitting over the posts 19, insure perfect registration of the member 14 on either the drag 12 or the cope 13.

The sand-penetrating and gas-dispersion elements 15 are so supported on the member 14 that, upon pressing the member 14 down onto the drag 12 or cope 13, the elements 15 serve to form channels 26 in the sand, leading to gas-dispersion points interiorly of the packed sand, and later to convey gas under pressure to those points for dispersion throughout the sand pack. Generally, there is one of these elements 15 for each pattern P arranged in the drag or cope.

Two difierent adaptations of these sand-penetrating and gas-dispersion elements 15 are shown in the drawings. The primary adaptation is shown in Figs. 1, 2 and 6. An alternate adaptation is shown in Figs. 7 and 8.

In the adaptation shown in Figs. 1 and 2, the elements 15 extend transversely through the member 14 to provide oppositely disposed parts 15a and 15b serving first to form the channels 26 in the sand and subsequently to feed the gas under pressure to the points of dispersion at the ends of the channels 26. Obivously, these elements 15 are suitably bonded in place to the member 14 so as to fix their positions thereon and also to preclude gas leaks from the chamber 20.

The ends of the elements 15 are sealed and preferably rounded or tapered to somewhat a point. The parts 15b have apertures 27 formed therein, slightly inward from the sealed or tip end, for the discharge of gas entering the elements 15 through the apertures 28 within the chamber 20.

The respective elements parts 15a and 15b extend equidistance on opposite sides of the member 14 so that they penetrate the sand the same distance. As shown in Figs. 1 and 2, these parts 15a and 1512 are all of uniform length on opposite sides of the member 14. However, they may be of unequal length on opposite sides of the member 14, as shown in Fig. 6, when this apparatus is to be used with patterns P of differing sizes in one mold.

In any adaptation of this apparatus, the length of the elements 15 is such that upon completely penetrating the sand the gas-dispersion points of the channels 26 are formed closely contiguous to the several patterns P in the mold.

The suspension yoke 16 is here shown of rectangular C-form with the arms 29 apertured adjacent their ends to provide bearings for the trunnions 23 on the member 14. The yoke 1'6m'ount's a connection 32 on its cross-bar 31 to some suitable overhead reciprocating mechanism (not shown) the manual-controlled operation of which will raise and lower the member 14 in perfect axial alinement with the posts 19 and thereby insure proper super imposed registration of the member on the drag 12 or cope 13.

The use of this one adaptation of the improved molding-sand gas-hardening apparatus is as follows:

Patterns P are suitably arranged on a positioning plate 33and secured to the base plate 17. As herein shown, the patterns P are for small pistons 34. They are set in openings in the positioning plate 33 and removably secured to the plate 17 by screws 36.

The drag 12 then is set in place on the plate 33with the posts 19 extending through the apertured extensions 21. The usual molding sand is filled in and tamped around the patterns P and leveled off across the top of the drag 12.

By a manual control of the overhead reciprocating mechanism, to which the yoke 16 is attached by the connection 32, the member 14, with the element parts 15a advancing, is lowered onto the posts 19 as the element parts 15a initiate their penetration into the sand axially of the respective patterns P. Since the ends of these element parts 15:: are sealed, no sand is permitted to enter the elements 15 andlater clog the apertures 27 in the parts .The member 14 having come into registering contact with the drag 12, the action of the overhead reciprocating mechanism for the yoke 16 is reversed and the member 14 retracted to a point above the drag 12. The member 14 is then turned 180 degrees on the yoke 16 to dispose the element parts 15b in advancing position when the memher is again lowered onto the posts 19 and into registering contact with the drag. Upon this relowering of the member 14, the element parts 15b enter the channels 26 formed by the prior penetration of the element parts 15a.

With the member 14 again in registering contact with the drag 12, the valve control for the CO gas pressure source is operated to admit gas through the inlet 24 to the chamber of the member 14. Passing through the apertures 28, the gas flows down through the element parts 15b for discharge from the apertures 27 and disper sion out through the sand surrounding the patterns P.

As is well known, the CO gas penetrates all portions of the sand and very quickly hardens it to a condition suitable to permit the ready handling of the mold, removal of the patterns, and the later pouring of the molten metal.

The hardening being effected, the valve control is turned 011 and the member 14 is elevated to withdraw the element parts 15b from the sand. The drag is then removed from the support 11 and set aside in an inverted position for later superimposition thereon of the companion cope, preparatory to pouring the molten metal for the castings.

Concurrently or subsequently, the cope 13 has similar patterns P arranged on a positioning plate 33' placed on the frame plate 17 and the cope 13 set on the plate 33.

. The usual sand is filled in and tamped around the patterns whereupon the aforesaid sequence of operations with the member 14 is repeated.

The operations for the cope 13 being completed, it is removed from the support 11, the patterns are withdrawn and the cope is superimposed on and locked to the drag 12 in the conventional manner.

Subsequently, molten metal is poured into the gate 37 whence it runs through the flow paths 38 to the several cavities left by the withdrawal of the patterns P.

Although the member 14 is shown in Figs. 1 and 2 mounted for vertical reciprocation and turning on the sus pension yoke 16, it should be understood that the member 14, with its oppositely-extending needle elements 15, could be used with the drag and cope of a molding flask wholly independent of such a suspension means. That is, it could be manually placed on the posts19 and the element parts 15a pressed down into the sand the limit permitted by the contact of the member 14 with the drag or cope, and then lifted out, and the member turned over and replaced on the posts 19 with the other element parts 15b inserted into the channels 26.

In the adaptation shown in Figs. 7 and 8, the tubular elements 15' extend from one side only of the chamber member 14 and are open at bothends. This member 14 mounts an auxiliary member '39, with a chamber 44, connected to valves 41 retractably seatable in the openings 42 of the respective elements 15.

The elements 15' are a bit larger in diameter than the elements 15 since the former have to accommodate the valves 41. These elements 15' span the member 14 with the inner open ends 43 communicating with the auxiliary chambered member 39. Apertures 46 afford communication between the gas chamber 20 and the chamber 39 and elements 15. p

The auxiliary member 39 is reciprocably supported on the member 14 by any suitable means. The peripheries of the two members 14 and 39 have secured thereto an extensible gas-seal 47 which permits a relative shifting of the members 14 and 39 but precludes the escape of gas therefrom.

' The valves 41, as here shown, are cone-shaped for seating into cone-shaped openings 42. Stems 48 connect the respective valves to the auxiliary member 39. Thus the gravitational resting of the auxiliary member 39 on the member 14 seats the several valves 41 to close the openings 42 in the respective elements 15' and preclude the entrance of sand into the elements 15' when they are penetrating the sand to form gas-dispersion channels. The gas-pressured elevation of the auxiliary member 39 on the member 14, when the CO gas under pressure is admitted to the chamber 20, retracts the valves 41 to permit the escape of gas through the openings 42 in the several elements 15 for dispersion through the sand to efiect the hardening thereof in the flasks.

To provide for the emergency of the gas pressure being insufiicient to elevate the auxiliary member 39 and retract the valves 41, a bracket 49 (see Figs. 8 and 9) may be secured to the member 14 for disposition above the auxiliary member 39. A screw 51 threaded through a nut 52 hearing on the bracket and mounting a handwheel 53, permits a manual turning of the nut and hence reciprocation of the auxiliary member 39 with respect to the'member 14.

This modified form of apparatus, although not so shown here, also could'be suspended from a verticallyreciprocable yoke similar to that shown in the previouslydescribed adaptation (see Figs. 1 and 2). However, the member 14 in that case would not require to be rotated on the suspending yoke.

The operation of this modified form of apparatus, shown in Figs. 7, 8 and 9, is as follows:

Upon the patterns P being positioned on the appropriate supporting plate 33 or 33' and the drag or cope than placed around the patterns P, sand would be filled in and tamped'around the patterns. The member 14and its associated auxiliary member 39--'would then be placed above the drag (or cope) and lowered to penetrate the elements 15' into the sand. The valves 41 being seated to close their respective openings 42, no sand could obtain entrance to the interior of the elements 15'. Upon the member 14 being pressed into registering contact with the drag or cope, the CO gas control would be opened to admit gas to the chamber 20 of the member 14. Escaping through the apertures 46 into the chamber 44 of the auxiliary member 39, this gas would elevate the member 39 and retract the valves 41 in the several elements 15'. 7 Immediately the gas will be discharged through the openings 42 and for dispersion throughout the sand to effect its hardening.

As soon as the sand is sufiiciently hardened, the gas is turned off and the auxiliary member 39 settles back into contact with the member 14. Thereupon the valves 41 are shifted to close the openings 42 in the several elements 15'. The apparatus is removed and the drag and cope arranged for the casting operation as previously described.

In the event the gas pressure should be insuflicient to efiect the requisite elevation of the auxiliary member 39 on the member 14 the turning of the hand wheel 53, shown in Figs. 8 and 9, may be used to efiect the successive retraction and seating of the valves 41 in the several elements 15'.

The main advantages of this invention reside in the ability to more thoroughly and quickly impregnate the mold sand with the hardening gas and thus more rapidly condition the mold sand for the metal pouring process; and in the simplicity of the apparatus structure whereby the CO hardening process can be readily and economically applied to mass production casting or molding procedures.

Other advantages are to be found in that the improved apparatus of this invention assures complete penetration of the hardening gas to the molten metal contacting surfaces of the sand cores as Well as throughout the body of the sand; in the injection needle arrangement whereby clogging of the outlet orifices is obviated; in the relatively low cost of the apparatus required for substantially any type of sand casting work; and in the fact that the improved apparatus is capable of injecting the hardening gas to every part of the mold body simultaneously and regardless of the intricacy of the mold pattern.

Although several specific embodiments of this invention have been herein shown and described it will be understood that numerous details of the constructions shown may be altered or omitted without departing from the spirit of this invention as defined by the following claims.

I claim:

1. A molding-sand gas-hardening apparatus comprising, a gas-chambered member dimensioned for superimposed positioning on a molding flask, and a plurality of needle elements transversely secured to the member on opposite sides thereof and projecting therefrom, the elements on one side of the member being hollow and communicating with the chamber thereof, said elements having the ends thereof apertured, and the elements on the other side of the member registering with the first mentioned elements and having the ends closed, the last mentioned elements being penetrable into the flask-supported sand as the member is pressed into superimposed relation on the flask to form channels in the sand for the subsequent reception of the apertured elements to disperse gas interiorly of the sand when the member is reversed and again pressed into superimposed relation on the flask.

2. A molding-sand gas-hardening apparatus comprising, a gas-chambered member dimensioned for superimposed positioning on a molding flask, and a plurality of tubular elements extending transversely through the member to project from opposite sides thereof and communicating with the chamber therein, the elements on one side of the member having the ends thereof closed and the elements on the other side of the member having the ends apertured, the elements on the one side of the member being penetrable into the flask-supported sand as the member is pressed into superimposed relation on the flask to form channels in the sand for the subsequent reception of the apertured elements to disperse gas interiorly of the sand when the member is reversed and again pressed into superimposed relation on the flask.

3. A molding-sand gas-hardening apparatus comprising, a gas-chambered member dimensioned for superimposed positioning on a molding flask, a plurality of needle elements transversely secured to the member and projecting from opposite sides thereof, the elements on one side of the member having the ends thereof closed and the elements on the other side of the member being hollow and communicating with said chamber, the last mentioned elements having their ends apertured, the elements on the one side of the member being penetrable into the flask-supported sand as the member is pressed into superimposed relation on the flask to form channels in the sand for the subsequent reception of the apertured elements to disperse gas interiorly of the sand when the member is retracted and reversed and then again pressed into superimposed relation on the flask, and reciprocable means rotatably supporting the chambered member thereon to permit the retracted reversal of the member relative to the flask.

4. A molding-sand gas-hardening apparatus comprising, a molding-flask support-frame having a pair of vertically-disposed posts for fixedly positioning a flask on the frame for packing sand therein, a gas-chambered member dimensioned and formed for sliding engagement with the posts for superimposed positioning on the flask, and a plurality of needle elements mounted transversely on the member to project from opposite sides thereof, the elements on one side of the member having the ends thereof closed and the elements on the other side of the member being hollow and communicating with the cha.mber thereof, the last named elements having the ends thereof apertured, the said member being first positionable on the posts and pressed into superimposed relation with the flask to penetrate the closed end elements into the sand to form channels therein, the member being then reversably positionable on the posts and pressed into superimposed relation with the flask to press the apertured elements into the channels in the sand formed by the penetration of the sealed elements.

5. A molding-sand gas-hardening apparatus comprising, a molding-flask support-frame having a pair of vertically-disposed posts for fixedly positioning a flask on the frame for packing sand therein, a gas-chambered member dimensioned and formed for sliding engagement with the posts and for superimposed registration on the flask, a plurality of tubular needle elements extending transversely through the member each projecting an equal distance from opposite sides thereof and communieating with the chamber therein, the element portions projecting on one side of the member having the ends thereof closed and the element portions projecting on the other side of the member having the ends thereof apertured, the member being first positionable on the posts and pressed into superimposed registration with the flask to penetrate the closed end element portions into the sand to form channels therein, the member being then reversably positionable on the posts and pressed into superimposed registration with the flask to press the apertured end element portions into the channels in the sand formed by the penetration of the closed end element portions, and a yoke vertically reciprocable axially above the support frame and rotatably mounting the member thereon to permit retraction and reversal of the member above the flask to aline the apertured element portions with the channels formed in the sand by the closed end element portions.

References Cited in the file of this patent UNITED STATES PATENTS 240,969 Cook May 3, 1881 429,994 Botter June 10, 1890 445,510 Black Jan. 27, 1891 1,010,643 Kramer Dec. 5, 1911 1,717,914 Campbell June 18, 1929 1,979,541 Gunn Nov. 6, 1934 (Other references on following page) 8 OTHER REFERENCES Gotheridge et a1: Hardening Sand with CO Foundry, March 3, 1956.

Foundry (B) publication Carbon-dioxide Process,

5 May 12, 1955.

Foundry Trade Journal, May 12, 195 6. Pages 505-506 relied on.

&, and 

